CVE-2026-77248

8.6 HIGHpublic exploit available

Published 2026-09-22 · Updated 2026-09-28

AI risk analysis

Summary: The flaw allows unauthenticated network callers to read files accessible to the MCP process and upload them to Jira or Confluence, posing a significant security risk.
Exploitability: Exploitation is relatively straightforward, requiring an unauthenticated network caller with access to the streamable HTTP transport.
Blast radius: If exploited, the attacker can read sensitive files and upload malicious content to Jira or Confluence, impacting the confidentiality and integrity of the system.
Detection: No reliable host or network indicator is derivable from the published description.
Prioritized remediation: Upgrade to version 0.22.0 or later.

auth-bypassfile-readuploadweb

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD description

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the streamable HTTP transport accepts requests without a user identity and falls back to operator credentials, while upload_attachment accepts an unrestricted file_path. An unauthenticated network caller can read files available to the MCP process, upload them to an attacker-selected Jira issue or Confluence page, and retrieve the contents. The advisory traces the vulnerable input and processing flow through streamable-http, UserTokenMiddleware, upload_attachment, file_path, and _get_fetcher, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N

Weaknesses

CWE-22, CWE-306

Vendors

mcp-atlassian

Products

mcp atlassian

Public exploit & PoC references

https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460[Patch]
https://github.com/sooperset/mcp-atlassian/pull/1448[Issue Tracking, Patch]
https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0[Release Notes]
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-cc5h-2pwp-pvcc[Vendor Advisory]
https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-cc5h-2pwp-pvcc[Vendor Advisory]

All references

Source data: NVD (nvd.nist.gov), public domain. Exploit-DB.ai adds local AI analysis for defensive use only.

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